197506-83-5Relevant articles and documents
Triphenylphosphine/1,2-Diiodoethane-Promoted Formylation of Indoles with N, N -Dimethylformamide
Zhu, Yu-Rong,Lin, Jin-Hong,Xiao, Ji-Chang
supporting information, p. 259 - 263 (2021/11/22)
Despite intensive studies on the synthesis of 3-formylindoles, it is still highly desirable to develop efficient methods for the formylation of indoles, due to the shortcomings of the reported methods, such as inconvenient operations and/or harsh reaction conditions. Here, we describe a Ph3P/ICH2CH2I-promoted formylation of indoles with DMF under mild conditions. A Vilsmeier-type intermediate is readily formed from DMF promoted by the Ph3P/ICH2CH2I system. A onestep formylation process can be applied to various electron-rich indoles, but a hydrolysis needs to be carried out as a second step in the case of electron-deficient indoles. Convenient operations make this protocol attractive.
C3-Formylation of Indoles in Continuous Flow
Sung, Ha Kyoung,Kim, Dong Hyun,Kim, Joon Seok,Park, Chan Pil
supporting information, p. 388 - 392 (2020/12/30)
We have developed a continuous flow C3-formylation technique for indoles using hexamethylenetetramine (HMTA) and iodine. A mixed solvent system of DMF–H2O (1:1, vol/vol) completely dissolves reagents and prevents clogging of microchannels during fluid flow. The continuous flow technique provides maximized mixing and excellent heat transfer efficiency. Thus, flow chemistry accelerates the rate of C3-formylation of indoles in the absence of a strong acid, base, or metal catalyst. We show that high yields of C3-formylated indoles (up to 83%) can be obtained at 150°C when the residence time is as low as 8 min.
Synthesis of 3-Formylindoles via Electrochemical Decarboxylation of Glyoxylic Acid with an Amine as a Dual Function Organocatalyst
Lin, Dian-Zhao,Huang, Jing-Mei
supporting information, p. 5862 - 5866 (2019/08/26)
A new method for 3-formalytion of indoles has been developed through electrochemical decarboxylation of glyoxylic acid with the amine as a dual function organocatalyst. The amine facilitated both the electrochemical decarboxylation and the nucleophilic reaction efficiently, whose loading can be as low as 1 mol %. This protocol has a broad range of functional group tolerance under ambient conditions. The gram-scale experiment has shown great potential in the synthetic application of this strategy.
